Drill-chuck.



P. PFEIFER.

' DRILL CHUCK.

APPLICATION FILED MAY 20, 1909.

' Patented Dec. 8, 1908.

ATTORNEYS PETER PFEIFER, OF DURHAMVILLE,- NEW YORK.

DRILL-annex.

No. 9o5,919.

Specification of Letters Patent.

Patented Dec. 8, 1908.

r Application filed May 20, 1908: Serial No. 433,864.

To all whom it may concern: 7

Be it known that I, PETER P-FEIFER, of Durhamville, in the county of Oneida and State of New York, have invented .certain new and useful Improvements in Drill Chucks; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to which it appertains to make and use'the same, reference being had tothe accompanying drawings, and. to the letters of reference'marked thereon, which form part of this specification.

The object of my present invention isto provide'an improved.drill chuck, which. is

simple in construction, eilicient in operation and well adapted tq-meet the requirements of such a device in actual use.

, Figure 1 shows a side elevation 'of my improved chuck with a drill in position therein. Fig. 2 is a longitudinal. sectional view of the same. Fig. 3 is a cross section on line" I 3, 3 of Fig. 2. vFig. 4 is a cross section on tion shown in Figs. 1 to; inclusive.

line 4:, t of Fig.2. Fig. 5 is a side elevation of a clampingbushin'g which may be employed in connection with the drill chuck for handling drills of reduced shank diameters shown in connection vyitlra drill in position therein. Fig. .6 'is a longitudinal sectional view of the same. "Fig. 7 is. a cross. section taken on line .7, 7 of Fig. 6. Fig; 8 shows a jaw of a-modified form of construction with the shank ofa bitin positionin connection therewith. Fi 9 is a section through a pair of'jaws o .the construction shown lfi Flg. 8, together with the shank "of off from the body it will be followed up by abit in positiontherein taken on line corre-- sponding to 9, 9 of Fig. 8. Fig. 10 is a perspective view of a baseplate with fingers employed in' connection with the construc- .'Referri ng to the reference letters and ures ma more particular description, 11 indicates the chuck body which is of general cylindrical form and preferably provlded in its base end with a socket-to receive the spindie 12 by means ofv which the chuck is mounted in a drill press lathe or other suitable machine. In the opposite end the body is provided with a tapering or conical socket 112, which receives a set of jaws 14, which.

taze'n together are externally of a general co ical form' adapted to fit the socketll As to their inner faces when taken together, the set' of jaws are adapted to provide a 'one end of the spring -18, which is intro body: Extending across the space which redrill shank opening adapted to receive the bearupon or rest against a base plate 16,

which. is of sufliciently reduced diameter to pass to its innermost position in the' ssocket without wedging and is provided with fin-' gers 17 received in cracks or open spaces between the adjoining sides of the jaws. These fingers 17 are preferablythin, light, resilient material and made corrugated or wavy,

whereby they'act as springs to'spread the jaws when opening but with or withoutthis function provide separators for the aws and mutual supporting means for the aws and plate when notforced together into the socket. The base plate 16 serves to even the jaws up longitudinally and as a bearing for.

duced in the lower end .of the socket 11 and confined under pressure operating to force the jaws-outwardly with reference tothe socket. A cap 19 is provided over the end of the chuck which has an opening suitable8-0 to allow the passage of the drill shank, and is internally screw-threaded and" engages with screw threads on the end of the chuck ceives the drill shank and engaging at either end in the jaws 14 is provided a positlve drivepin 20. The inner face of the dllll shank may be provided with a notch or re- Cess to fit over and engage with this positive drive pin 20..

It is evident that as the I screw cap is turned the jaws 14 impelled by the spring 18 for a reasonable distance; The jaws w ll also. be .opened in a circumferential way by the op.-

I eration of the fingers 17 When su fliciently opened up a drill shank may befintroduced 'between'the jaws,-when b screwing the cap I on to the chuck body the aws will be force into the conical socket 11 and closed together until they tightly grip the shank of the drill. At the same time care may be exercised to have the notch in the lower end of-the'drill engage on the positive drivepiir I j 20. The friction grip'on the ]8.WS Of' the drill will ordinarily be suflicient to drive it. but the positive drive insures the drill being held against rotation even though the aws are not gripping with suflicient power.

Ordinary sizes of drills' from say three" ameter.

' together by a cross pin 27, which engages in each loosely. The slight heads on the pin 27 prevent the parts from becoming separated and at the same time allows them to be freely closed together by the jaws of the drill chuck in gripping a shank of smaller diameter. The pin 27 also serves as a positive drive for the drill inserted in a bushing,

' while the'bushingin its base end is provided' with a slot 28 adapting it to engage with the positive drive pin 20 of the chuck jaws. In order to concentrate the grip of the bushing on the outer end, there may be provided in 7 one of the parts as 26 an adjustable screw 29,

which'the' opposite part is adapted to bear. It is evident that when the bushing is inserted in the-drill chuck and a drill shank is inserted within the bushing, upon tightening the chuck the chuck j awswill close the bushing on to the shank of the drill tightly ""gripping it, and the positive .drive is still secured. y

In order to adapt the chuck for use with wood bits having heads square on cross section and tapering in form in lieu of the said jaws 14, I may substitute a pair of jaws as .30. The pair of jaws 30 as to their exteriors are of the general conical form of the socket in the chuck body, while as to .their inner faces they are provided with half sockets adapted to fit and receive the square head I, as 31 of a wood bit. The operation of this form of construction is similar to that previously described and quite obvious. It, however, might be noted that the cap needs to be loosened to a larger extent to allow the jaws to open sufiiciently to place or withdraw the bit head.

Other modifications and changes in and from the construction herein described may be made without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent is:

1. The combination in a chuck of a body having a conical socket, a set of jaws together of the same general conical form eX- ternally as the socket and havin a shank opening within, a positive drive pin extending across the shank opening and mounted in the jaws, and a cap screw-threaded on tothe body and arranged to force the jaws into the socket, substantially as set forth.

2. The combination in a chuck of a body I having a conical socket, a set of jaws together of the same general conical form externally as the socket and having a shank opening within, a base plate engaging against the inner ends of the jaws having fingers projecting between the jaws, an expelling spring behind the base plate in the socket, and a screw cap on the body arranged to force the jaws into the socket, substantially as set forth. g

3. The combination in a chuck of a body having a conical socket, a set of jaws together of the same general conical form externally as the socket and having a shank receiving opening within, a base plate engaging against the inner ends of the jaws having resilient spring fingers projecting between the jaws, an expelling spring in the jaw socket beneath the jaws and base plate,

and a screw cap on the body arranged to force the jaws into thesocket, substantially as set forth.

I l. A clamping bushing consisting of two substantially semi-cylindrical parts together having a longitudinal internal socket, a loose pin spanning the inner end of the internal socket and forming a holding connection between the parts and a positive drive. for a tool'having a recessed end inserted in the socket, substantially as set forth.

In witness whereof, I have affixed my signature, in presence of two witnesses, this 15th day of May 1908.

- PETER PFEIFER.

l Witnesses SARAH E. CLARK, EMMA S. HESSE. 

